Ezo vs Yezo

Ezo and Yezo both are nouns.

Word	Noun	Adjective	Verb	Adverb
Ezo	Yes	No	No	No
Yezo	Yes	No	No	No

As nouns, Ezo and Yezo are synonyms defined as:

Ezo and Yezo: the second largest of the four main islands of Japan; to the north of Honshu

Other synonyms of Ezo include Hokkaido.

Ezo (noun)	Yezo (noun)
the second largest of the four main islands of Japan; to the north of Honshu	the second largest of the four main islands of Japan; to the north of Honshu